"""Provision Node.js and the shared nerimity.js install inside the Space container.

Gradio Space images ship Python, not Node. Rather than depend on whatever `apt` would give
us, we download the official Node LTS tarball on cold start (~25 MB compressed, ~20 s) into
/home/user/.node and install @nerimity/nerimity.js once into a shared node_modules that all
bots resolve through NODE_PATH.

(The plan called this bootstrap_node.sh; it's Python so failures surface in the same log
stream as everything else instead of vanishing into a subshell.)
"""
from __future__ import annotations

import os
import shutil
import subprocess
import tarfile
import urllib.request
from pathlib import Path

NODE_VERSION = os.environ.get("BB_NODE_VERSION", "v22.14.0")
NODE_HOME = Path(os.environ.get("BB_NODE_HOME", "/home/user/.node"))
DATA_DIR = Path(os.environ.get("BB_DATA_DIR", "/home/user/data"))
SHARED_MODULES = DATA_DIR / "node_modules"

NERIMITY_PKG = "@nerimity/nerimity.js"


def _log(msg: str) -> None:
    print(f"[node] {msg}", flush=True)


def ensure_node() -> str:
    """Return a usable `node` binary path, downloading the runtime if needed."""
    existing = shutil.which("node")
    if existing:
        _log(f"using system node: {existing}")
        return existing

    node_bin = NODE_HOME / "bin" / "node"
    if node_bin.exists():
        _log(f"using cached node: {node_bin}")
        os.environ["PATH"] = f"{NODE_HOME / 'bin'}:{os.environ.get('PATH', '')}"
        return str(node_bin)

    name = f"node-{NODE_VERSION}-linux-x64"
    url = f"https://nodejs.org/dist/{NODE_VERSION}/{name}.tar.xz"
    tmp = Path("/tmp") / f"{name}.tar.xz"
    _log(f"downloading {url}")
    urllib.request.urlretrieve(url, tmp)  # noqa: S310 - fixed, trusted URL

    _log("extracting")
    NODE_HOME.parent.mkdir(parents=True, exist_ok=True)
    with tarfile.open(tmp) as tf:
        tf.extractall("/tmp")  # noqa: S202 - official tarball
    extracted = Path("/tmp") / name
    if NODE_HOME.exists():
        shutil.rmtree(NODE_HOME, ignore_errors=True)
    shutil.move(str(extracted), str(NODE_HOME))
    tmp.unlink(missing_ok=True)

    os.environ["PATH"] = f"{NODE_HOME / 'bin'}:{os.environ.get('PATH', '')}"
    _log(f"node ready: {node_bin}")
    return str(node_bin)


def ensure_nerimity(node_bin: str) -> bool:
    """Install the Nerimity SDK once into a shared node_modules. Returns True if usable."""
    marker = SHARED_MODULES / "@nerimity" / "nerimity.js" / "package.json"
    if marker.exists():
        _log("nerimity.js already installed")
        return True

    DATA_DIR.mkdir(parents=True, exist_ok=True)
    pkg = DATA_DIR / "package.json"
    if not pkg.exists():
        pkg.write_text('{"name":"bbuilder-host-deps","private":true}\n')

    npm = Path(node_bin).parent / "npm"
    npm_cmd = [str(npm)] if npm.exists() else ["npm"]
    _log(f"installing {NERIMITY_PKG}")
    try:
        res = subprocess.run(
            npm_cmd + ["install", "--no-audit", "--no-fund", NERIMITY_PKG],
            cwd=str(DATA_DIR),
            capture_output=True,
            text=True,
            timeout=300,
            env={**os.environ, "PATH": f"{Path(node_bin).parent}:{os.environ.get('PATH','')}"},
        )
    except Exception as exc:  # noqa: BLE001
        _log(f"install failed: {exc}")
        return False

    if res.returncode != 0:
        _log(f"npm install failed:\n{res.stderr[-1500:]}")
        return False
    _log("nerimity.js installed")
    return marker.exists()


def version(node_bin: str) -> str:
    try:
        return subprocess.run([node_bin, "--version"], capture_output=True, text=True,
                              timeout=15).stdout.strip()
    except Exception:  # noqa: BLE001
        return "unknown"